A sail furler for a sail boat and method for furling a sail for reefing or storage and for unfurling a sail for use. Furling and unfurling of the sail may be accomplished from the cockpit of the sailboat. A mandrel is mounted to the mast extending generally parallel to the boom and attached to the aft end of boom by an aft plate. The mandrel is mounted in bearings and provided with a removable crank for rotation. The mandrel is connected to the mast by a universal joint and bearing structure over which is provided an outer cylinder. A cylinder and resilient sleeve may be provided on the mandrel. A reef brake extends from the mandrel into contact with the boom to prevent rotation for reefing the sail. A slide guard may be mounted at the mast end of the mandrel.